I would suggest you not to buy followers as most of them will be self created profiles and spammers which will be waste of time and efforts and as well as money. To get more genuine followers, you can do the below:

1. Select a field or topic that you are good in.2. Start adding the top twitter personalities in that field, after this you can see some increase in your followers.3. Start posting valuable content and resources.4. Be active and comment on valuable tweets posted by others.5. Try following users who are only worth following.

This way you can get more followers and importantly they would be genuine and looking for more information from you

Getting followed by natural way is always good. There are other spammy techniques although but I may not suggest you to do so.. better you just follow people you like and if they think they may follow you back .Best regards,Aaron.

1.Set up a welcoming 'thank you for following me' message for your new twitter followers.2.Make your twitter profile as friendly and trustworthy looking as your welcome message.3.Follow your followers and see what they are tweeting about.4.Be helpful to non-followers.